tools: Fix handling of empty argv in various minor GLib tools

This won’t really affect anything, but we might as well fix them to not
crash if called with an empty `argv` by someone (ab)using `execve()`.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

gio/gio-querymodules.c

@@ -161,7 +161,7 @@ main (gint   argc,
 {
   int i;
 
-  if (argc == 1)
+  if (argc <= 1)
     {
       g_print ("Usage: gio-querymodules <directory1> [<directory2> ...]\n");
       g_print ("Will update giomodule.cache in the listed directories\n");